First principles investigation of anionic redox in bisulfate lithium battery cathodes

The search for an alternative high-voltage polyanionic cathode material for Li-ion batteries is vital to improve the energy densities beyond the state-of-the-art, where sulfate frameworks form an important class of high-voltage cathode materials due to the strong inductive effect of the S$^{6+}$ ion. Here, we have investigated the mechanism of cationic and/or anionic redox in Li$_x$M(SO$_4$)$_2$ frameworks (M = Mn, Fe, Co, and Ni and 0 $\leq$ x $\leq$ 2) using density functional calculations. Specifically, we have used a combination of Hubbard $U$ corrected strongly constrained and appropriately normed (SCAN+$U$) and generalized gradient approximation (GGA+$U$) functionals to explore the thermodynamic (polymorph stability), electrochemical (intercalation voltage), geometric (bond lengths), and electronic (band gaps, magnetic moments, charge populations, etc.) properties of the bisulfate frameworks considered. Importantly, we find that the anionic (cationic) redox process is dominant throughout delithiation in the Ni (Mn) bisulfate, as verified using our calculated projected density of states, bond lengths, and on-site magnetic moments. On the other hand, in Fe and Co bisulfates, cationic redox dominates the initial delithiation (1 $\leq$ x $\leq$ 2), while anionic redox dominates subsequent delithiation (0 $\leq$ x $\leq$ 2). In addition, evaluation of the crystal overlap Hamilton population reveals insignificant bonding between oxidizing O atoms throughout the delithiation process in the Ni bisulfate, indicating robust battery performance that is resistant to irreversible oxygen evolution. Finally, we observe both GGA+$U$ and SCAN+$U$ predictions are in qualitative agreement for the various properties predicted. Our work should open new avenues for exploring lattice oxygen redox in novel high voltage polyanionic cathodes, especially using the SCAN+$U$ functional.Comment: Draft and supporting information included, 40 pages tota

GASTRIC ANTIULCER AND ULCER HEALING EFFECTS OF PUNICA GRANATUM L. PEEL EXTRACT IN RATS: ROLE OF OFFENSIVE AND DEFENSIVE MUCOSAL FACTORS AND OXIDATIVE STRESS

Objective: The present work incorporates the study of gastric antiulcer and ulcer healing effects of dried Punica granatum (PG) peel 50% ethanol extract (PGE) in rats.Methods: PGE (100 mg/kg) was administered orally once daily to rats either before or after induction of gastric ulcers (GU) for 7 d. Antiulcer effects of PGE were seen against acute GU, induced by pylorus ligation (PL), cold restraint stress (CRS), aspirin and ethanol while, ulcer healing in acetic acid (AA)-induced chronic GU in rats. Ulcer index (UI), gastric juice volume, acid-pepsin and mucin secretions and gastric mucosal glycoproteins, free radicals (LPO and NO) and antioxidants (SOD and GSH) were estimated.Results: PGE showed a decrease in UI in all GU models (45.6 to 79.7%, P<0.05 to P<0.001) indicating both protective and healing effects. PGE showed little or no effects on volume, acid-pepsin concentration and output but increased mucin secretion (55.1%, P<0.05) and mucosal glycoproteins (35.7%, P<0.05) in PL rats. CRS rats showed an increase in LPO and NO (48.4 to 58.3%, P<0.01) and SOD (21.8%, P<0.01) but decrease in GSH and CAT (33.1 to 44.8%, P<0.01 to P<0.001) compared with unstressed rats. PGE-treated CRS rats showed a decrease in LPO and NO (44.1 to 61.2, P<0.01 to P<0.001) and SOD (13.2%, P<0.01) and increase in GSH and CAT (43.8 to 48.7%, P<0.01 to P<0.001) compared with CRS rats.Conclusion: PGE seemed to have ulcer cytoprotective effects due to enhanced mucosal resistance and reduction in oxidative mucosal damage possibly via high antioxidant activity

Antioxidant Capacity and Radical Scavenging Effect of Polyphenol Rich Mallotus philippenensis

Mallotus philippinensis is an important source of molecules with strong antioxidant activity widely used medicinal plant. Previous studies have highlighted their anticestodal, antibacterial, wound healing activities, and so forth. So, present investigation was designed to evaluate the total antioxidant activity and radical scavenging effect of 50% ethanol fruit glandular hair extract (MPE) and its role on Human Erythrocytes. MPE was tested for phytochemical test followed by its HPLC analysis. Standard antioxidant assays like DPPH, ABTS, hydroxyl, superoxide radical, nitric oxide, and lipid peroxidation assay were determined along with total phenolic and flavonoids content. Results showed that MPE contains the presence of various phytochemicals, with high total phenolic and flavonoid content. HPLC analysis showed the presence of rottlerin, a polyphenolic compound in a very rich quantity. MPE exhibits significant strong scavenging activity on DPPH and ABTS assay. Reducing power showed dose dependent increase in concentration absorption compared to standard, Quercetin. Superoxide, hydroxyl radical, lipid peroxidation, nitric oxide assay showed a comparable scavenging activity compared to its standard. Our finding further provides evidence that Mallotus fruit extract is a potential natural source of antioxidants which have a protective role on human Erythrocytes exhibiting minimum hemolytic activity and this justified its uses in folklore medicines

A Comprehensive Review of the Evolution of Networked Control System Technology and Its Future Potentials

Networked control systems (NCSs) are attracting the attention of control system engineers. The NCS has created a paradigm shift in control system technology. An NCS consists of control loops joined through communication networks in which both the control signal and the feedback signal are exchanged between the system and the controller. However, its materialization faces several challenges as it requires the integration of advanced control and communication techniques. This paper presents an extensive review of NCSs from the perspective of control system design. The evolution of NCSs is broadly divided in three phases, namely NCSs prior to 2000, NCSs during 2001–2010, and NCSs from 2011 onwards. This division corresponds to the initial status, intermediate status, and the recent status of the developments in the design of NCSs. The advancement of different control techniques during these phases has been discussed comprehensively. This paper also describes the transition of control systems form continuous domain to networked domain, which makes it better than the traditional control systems. Some important practical applications, which have been implemented using NCSs, have also been discussed. The thrust areas for future research on NCS have also been identified